Multiple valve pump



Jan. 16, 1968 L, LOGUE 3,363,580

' MULTIPLE VALVE PUMP Filed Jan. 19, 1966 2 Sheets-Sheet l H nllllmll mIN VENT OR. LELAND H. 'LOGUE A TTQRNEZS Jan. 16, 1968 Filed Jan. 19,1966 L. H. LOGUE MULTIPLE VALVE PUMP 2 Sheets-Sheet 2 LELAND LOGUEAITORNEYS United States Patent 3,363,580 MULTIPLE VALVE PUMP Leland H.Logue, Denver, Colo., assignor to Denver Equipment Company, Denver,Colo., a corporation of Colorado Filed Jan. 19, 1966, Ser. No. 521,71811 laims. (Cl. 103151) ABSCT OF THE DISCLUSURE This invention relates toa flow through piston adapted for vertical reciprocating movement in avertically extending pump body to pump slurries. Such a piston comprisesa generally horizontally extending piston head of circular planfrom anda substantially greater diameter than thickness. The piston head isprovided with marginal sealing means for sealing contact with the wallof the pump body. A plurality of vertical flow passages extend throughthe head. These flow passages are preferably equally spaced radiallyabout the vertical axis of the head. An elastomeric sealing ring ismounted on the head about the upper margin of each of the passages. Thediameter of the seal ing ring is substantially the same diameter as thatof the passages. A clamping plate overlies the head and has a pluralityof vertical apertures formed therein and of such size as to overlie theouter margins of each sealing ring to clamp them in place of the head. Acentral guide pin and a plurality of peripheral guide pins extendvertically above the clamping plate and have reduced shank portionspassing through the clamping plate and secured to the head and formingshoulders to engage said clamping plate and to secure the position. Saidpiston also includes a plurality of balls.

This invention lies in the field of pumps for regulating and controllingthe flow of thickened .pulps or slurries and is directed particularly toan improved valving construction and arrangement which increasesefficiency and results in trouble-free performance and longer pump life.

Modern industrial and civic operations call for the handling andtransporting of many types of semi-fluid mixtures such as coal and oreslurries and pulps of many materials including sewage. Many varieties ofpumps are presently available which are suited to this type of work. Oneof the most satisfactory is a generally vertically arranged pump bodyhaving a bottom inlet with a check valve and a vertically reciprocatablepiston also provided with a check valve which draws the mixture inthrough the bottom inlet and raises it to the upper part of the pumpbody where it is discharged through a simple outlet opening at a levelwhich will produce the desired flow.

The rate of reciprocation of the piston is usually maintained constantand the length of stroke is varied to produce or modify the desiredquantity rate of flow. Such a pump normally has a single check valve atthe inlet and a single check valve centrally located in the piston head.These valves are poppet valves having large valve stems which extend inthe flow passages and greatly decrease their areas and flow capacities.The smaller pumps produce flows as low as five gallons per minute whilethe larger pumps produce flows as high as 500 gallons per minute. Itwill be readily seen that substantial flow restrictions seriously reducetheir efficiency.

In an effort to overcome this disadvantage the valves must have a longvertical stroke which in turn produces a long closing time during whichreverse flow can occur. This also tends to reduce the eficiency. In thelarger size pumps, for lines of six to ten inches, these poppet valves,which are usually iron or steel, are very large and heavy, many being inexcess of 100 pounds in weight. Consequent- Patented Jan. 16, 1968 Seely the closing action produces a severe pounding. When it is consideredthat such pumps operate at 25 to 40 strokes per minute it can be seenthat such continuous pounding drastically reduces pump life.

The present invention overcomes the difficulties mentioned above byproviding a construction which utilizes multiple valves for both theinlet and the piston, and in which the valves do not reduce the area ofthe flow passages and are so much lighter that the pounding effect iseliminated. Generally stated, the pump indicates a vertically extendinghollow pump body having an inlet in its lower portion and an outlet inits upper portion. A generally planar partition extends across the lowerportion above the inlet and is provided with a plurality of verticalcircular flow passages therethrough for upward flow or" the liquid-solidmixture in response to the pump suction. A valve ball is provided foreach of the valve seats formed at the upper terminus of the respectiveflow passages. It moves freely upward in response to the upward flow andseats by gravity promptly at the inception of reverse flow to retain themixture in the pump body.

The pumping action is produced by a vertically reciprocating pistonlocated in the pump body above the partition. The piston head isgenerally planar and horizontal like the partition and is similarlyprovided with a plurality of vertical flow passages and valve balls. Thepiston may extend entirely across the pump body and be provided with anysuitable sealing means for sliding sealing engagement with the wall ofthe pump body. However, it is preferred to make the piston head somewhatsmaller in diameter and use an annular diaphragm which is secured at itsinner margin to the piston head and at its outer margin to the pump bodyWall to avoid the sliding wear resulting from the handling of abrasivematerial. The balls seat by gravity and seal the piston during itsupward movement to raise the mixture through the pump body. When thepiston is lowered into the mixture retained in the lower part of thepump body, the balls are unseated by the relative upward flow of themixture through the piston head.

It has been determined that the maximum flow passage area for a givendiameter of piston or partition is obtained when three flow passages areprovided at equal distances from the central vertical axis and equallyangularly spaced about the axis. The diameter of each ball is betweenapproximately 145 percent of the diameter of the flow passage andpreferably about thereof to provide satisfactory seating while requiringa relatively small vertical movement to achieve maximum flow. When theballs are unseated, no part of them protrudes into the flow passages toreduce the effective flow area, with the result that maximum flow isobtained with any given size of passages.

In order to obtain quick and easy seating and unseating of the valveballs as well as minimum shock on closing, a proper relation should bemaintained between the specific gravity of the ball material and that ofthe mixture being handled. The commonly used cast iron or steel poppetvalves are very heavy and require excessive force to raise them fromtheir seats. The impact force on closing is correspondingly high and thecontinuous pounding is detrimental to the valves and seats and also therest of the structure, so that maintenance costs are high and totalmachine life is much shorter than it should be. It has been determinedthat when the valve balls of the present invention have a specificgravity in the approximate range of to 380 percent of that of the slurrythey are readily unseated by the upward flow force and they seat againwith very little shock. At the same time they are heavy enough to closequickly under gravity force. The usual slurries or mixtures normallyencountered in the field generally have an approximate specific gravitybetween about 1.05 to 2.5. One of the ball materials which has beenfound to be highly satisfactory is a high aluminum oxide ceramic havinga specific gravity of about 3.7 to 4.0. In addition to having the rightspecific gravity, this material is very hard and highly resistant toabrasion and its service life is at least as great as that of any otherpart of the system.

Various other advantages and features of novelty will become apparent asthe description proceeds in conjunction with the accompanying drawings,in which:

FIGURE 1 is a front elevational view of a pump incorporating theinvention;

FIGURE 2 is a sectional elevational view of the pump body and theworking elements housed therein; and

FIG. 3 is a plan view of the piston head and certain cooperatingelements.

The type of pump in which the invention is incorporated is generallyillustrated in FIG. 1 in which a structural steel base has mountedthereon a pump body 12, drive mechanism 14, and motion translationmechanism 16. The pump body is hollow and comprises a bowl shaped lowerportion 18 having a mixture inlet 26, and an upper cylindrical housingportion 22 having a trough shaped discharge outlet 24. It may also beprovided with a cover or splash plate 26.

The drive mechanism 14 includes a gear box 28 on which is mounted amotor 30 having a driving pulley 32 connected by belts 34 to drivenpulley 36 mounted on the shaft 38 of the gear reduction assembly, notshown, located within gear box 28. Shaft 40 extending from the gear boxcarries a disk 42 provided with an eccentric pin 44 serving as a crank.The lower end of connecting rod 46 is pivotally connected to pin 44 andthe rod extends upwardly to the motion translation mechanism 16.

Mechanism 16 includes a pair of upright columns 48, one at each side ofthe pump body 12, mounted fixedly at their lower ends on frame 10carrying at their upper ends a rocker shaft 50. A rocker block 52 ispivotally mounted on shaft 50 and carries a driving yoke or clevis 54extending to the left as seen in FIG. 1. A shaft 55 extends to the rightand is rigidly connected to the rocker block to transmit driving forcesthereto. Drive block 58 is slidably mounted on shaft 56 from end to endand is provided with a lateral extension 60 having a centrally locatedpivot 62 connected to the upper end of connecting rod 46. The free end64 of the extension is threadedly connected to adjusting shaft 66 whichis rotatably mounted at one end in rocker block 52 and provided with ahand wheel 68. The opposite end of shaft 66 is rotatably mounted inbracket 70 and is provided with a second hand wheel 72.

Shaft 66 may be rotated by either of the hand wheels to move drive block58 to any point along shaft 56, thus setting pivot 62. at any desireddistance from rocker shaft 50. Since the stroke of the connecting rod 46is constant because of its connection to crank pin 44, the adjustment ofblock 58 serves to vary the effective pumping stroke of the assembly.Pump shaft 74 is pivotally connected at 76 to clevis 54 to be verticallyreciprocated thereby when motor 30 is activated, and the length of itsstroke varies inversely with the distance between pivot 6-2 and rockershaft 50.

The principal details of construction of the mixture handling assemblyare illustrated in FIG. 2. While the entire basic pump body may be asingle casting it is preferred to make it in three parts as shown,including a cylindrical housing 22, a frusto-conical bowl portion 78 anda tapered lowermost bowl portion 80, to which is attached an inletflange 82 carrying inlet pipe 20. The various parts are secured togetherwith conventional bolts and nuts, using appropriate gaskets or sealingmaterial where necessary. Mounting ears 84 are provided for attachmentto a support such as base 10.

A check valve assembly in the lower portion of the bowl includes apartition 86 which may be a separate plate extending across the bowl butpreferably is cast integral with member 80. Three circular apertures 88extend vertically through the partition to serve as flow passages forthe slurry or other mixture to be pumped. They are preferably of thesame diameter and are equally spaced radially from the central verticalaxis 99 and are also equally spaced angularly about the axis. Anelastomeric sealing ring 92 is mounted at the upper terminus of eachpassage and is preferably of substantially the same diameter as thepassage. The rings are angle shaped in cross section with outwardlyextending flanges or lips. The rings are held in place by a clampingplate 94 having openings of such size and location that the plate willoverlie the flanges of rings 92. The clamping plate may be unitary ordivided into sectors individually clamping the rings.

Dual purpose guide pins 96 are provided and serve both to guide themovable portions of the valve assembly and to hold the clamping plate inplace. The pins have an upper portion which is polygonal in section toreceive a wrench, and a lower reduced portion 98 which is threaded to besecured in tapped holes 100 in the partition. The shoulder 10?. formedby the reduced portion engages the upper surface of clamping plate 94-to secure it as shown. One pin is mounted on the central axis and sixother pins are equally spaced about the margin of the plate to produce aseries of triangular guide sets.

A valve ball 104- is associated with each passage and has a diameterabout 30 percent greater than the diameter of the passage. With theseproportions the ball fits down into the seal ring sufficiently toprovide an adequate seal and yet needs to be raised only about onequarter of its diameter to provide an annular flow path at least aslarge as that through the passage. The guide pins are slightly spacedradially from each valve ball to allow ansolute freedom of verticalmovement while restricting its lateral displacement to a very smallamount.

It will be seen now that when a suction is produced above the checkvalve assembly just described, an up ward flow of a liquid-solid mixturewill occur through passages 88 and raise the valve balls off their seatsto the dotted line position. The mixture will flow around all sides ofthe ball without restriction, and maximum flow and maximum efficiencywill result. As mentioned above, the specific gravity of the ball isabout one and one-half to two times the specific gravity of the mixture,which minimizes the force necessary to raise it. At the same time theratio is great enough to permit the ball to return by gravity rapidly toits seat when the fiow ceases or starts to reverse. In addition, theshape and relation of the ball and seat are such that an annular venturiis formed Whenever the ball is raised to any extent. The upward flowthrough the venturi produces a pressure reduction which restrains theball against excessive upward movement on opening, and any reverse flowproduces a similar force which accelerates the closing. The rapidclosing is highly desirable because it minimizes the loss of mixturewhich has been raised.

The actual pumping effect is, of course, produced by the verticallyreciprocating piston 106 which is preferably located as shown directlyabove the partition and check valve for compactness. However, it is tobe under stood that the pump body may be made as laterally expansive asdesired and the piston can be completely laterally displaced from thepartition and check valve assembly. As shown, it is centered on thevertical axis 90, and housing 22 is cylindrical and coaxial with axis90. Piston 106 includes a horizontally extending generally planar head198 of circular planform made up of two substantially identical disks110, 112;.

The head may extend entirely across the housing and be equipped with aconventional sealing ring for sliding engagement with the wall ofhousing 22 but this is not desirable because of the abrasive characterof most of the material handled by pumps of this type. Instead, matchinggrooves 114, 116 and 118, 120 are formed in the parts 110, 112 and 22,78 respectively, and an annular diaphragm 128 of tough, flexiblematerial is provided. An inner marginal bead 122 is fitted into grooves114, 116 and an outer marginal bead 124 is fitted into grooves 118, 120and the parts are clamped together as shown to provide a completelysealed but relatively movable connection. If desired, Single grooves maybe provided at each margin and the diaphragm may have correspondingbeads.

The construction of the piston head and its associated parts issubstantially identical to that of the partition 86 and its associatedparts. Circular vertical passages 126 are formed through disks 112 and110 and are shaped and spaced the same as passages 88. The same sealingrings 92, clamping plate 94 and guide pins 95 are used, and the guidepins are threaded into the lower plate 112 to secure the entireassembly. Valve balls 104 are also identical and function generally inthe same Way. The plan view of FIG. 3 shows the relation of variousparts, including the triangular arrangement of the sets of guide pins 96around each of the passages 126 to allow free vertical movement of valveballs 104 but to restrict their lateral movement to a very limitedamount. Clamping plate 94 is cut away at three places as shown forclearance purposes and is further shown as actually divided into threesectors 130, which serve the same purpose as a unitary plate.

Piston head 108 is carried for its vertical reciprocating movement by aspider frame 132 comprising three arch shaped legs 134 rigidly securedto plate 110 as best seen in FIG. 3, and forming a junction 135 on axis90 above the piston head. A tapped hole 138 is formed in the junction toreceive the threaded end 140 of pump shaft 74. When the drive mechanism,previously described is activated, shaft 74 reciprocates vertically andraises and lowers piston 106.

Considering piston 106 to be at rest initially, valve balls 104 areseated on rings 92 and the piston is sealed. When the piston is raisedit will raise any mixture already above it for ejection thereof and drawmore mixture into the pump body below it. When the mixture rises to thelevel of outlet through 24 it will flow out. When the movement of thepiston is reversed, it will press down on the mixture below it. Suchaction will unseat the valve balls from the piston and result in a flowof the mixture upward past said unseated valve balls. Such action alsoinsures that the valve balls in the check valve assembly are seated uponcheck valve assemblys sealing ring 92. Actually, of course, no mixtureis raised during the down stroke of the piston. When the piston reachesthe bottom of its stroke, the valve balls will promptly seat by gravityand seal the piston for the next up stroke. Movement of the balls w llbe controlled and facilitated by the venturi action previouslydescribed.

It will be seen that during the period of flow through passages 88 and126 there is no structure in the passages to cut down their area andinterfere with flow, as in the case of poppet valves having stems whichare guided in the passages at all times. The multiple openings,particularly in sets of three as described, give maximum passage areafor a given size of piston or partition. The use of valve balls havingthe proper specific gravity makes for rapid and easy opening andclosing, and the comparatively low weight reduces pounding to a minimum.The material used for the valve balls is a high aluminum oxide ceramicproduced by the Coors Company under the trade name Coors A99. It has aspecific gravity of the order of 3.7 to 4.0, and a hardness of 9.8 onthe Mohs mineralogy scale of 10. The halls are used as fired and have asmooth textured surface finer than fine sanding. One of the advantagesof these balls over others, such as lead balls covered with rubber orrubber balls impregnated with powdered lead is that they are perfectlyuniform and balanced so that they have no tendency to strike the seatseccentrically, which delays sealing and damages the seats. Because oftheir hardness, they are practically immune to wear.

It will be apparent to those skilled in the art that various changes maybe made in the construction and arrangement of parts as disclosedwithout departing from the spirit of the invention, and it is intendedthat all such changes shall be embraced within the scope of thefollowing claims.

I claim:

1. A pump adapted for handling liquid pulp mixtures 0r slurries,comprising: a hollow pump body having a mixture inlet in its lowerportion and a mixture outlet in its upper portion; a horizontallyextending partition in the lower portion; a plurality of verticallydirected circular apertures forming flow passages through said partitionand spaced uniformly about the periphery of a circle in the plane ofsaid partition; each aperture having an annular valve seat; a valve ballassociated with each seat and freely vertically movable upwardly out ofcontact therewith to provide an annular flow path for upward movement ofa mixture through said partition and movable downwardly into contactwith each seat to form a seal therewith and prevent reverse flow; apiston in said pump body and vertically reciprocatable to pump a mixtureupward through said pump body to said outlet; said piston having ahorizontally extending head provided with means to sealingly engage thewall of the pump body; a plurality of vertically directed aperturesforming flow passages through said head and spaced uniformly about theperiphery of a circle concentric with the vertical axis of said head;each aperture having an annular valve seat; a valve ball associated witheach seat and freely relatively movable vertically upward out of contacttherewith to provide a flow path for relative upward movement of amixture through said head and relatively movable downward into contactwith each seat to form a seal therewith and prevent reverse flow; saidpartition and said piston head each being provided on its upper surfacewith an elastomeric ring surrounding each flow passage for sealinglyreceiving a valve ball; an apertured clamping plate having aperturemargins overlying marginal portions of said elastomeric rings;vertically extending guide pins for limiting lateral movement of saidvalve balls; said guide pins passing through said clamping plates andbeing threadedly secured to the partition and piston head respectivelyto lock said clamping plates in clamping relation; and means to raisesaid head with its valves closed to pump mixture upward in the pump bodyto the outlet and draw additional mixture through the partition, and tolower said head with its valves open into the additional mixture in thelower portion of the pump body.

2. A pump as claimed in claim 1; said piston head and the wall of saidpump body being circular in planform; and said means to sealingly engagethe wall of the pump body comprising an annular flexible diaphragmhaving an inner margin secured to the piston head and an outer marginsecured to the wall of the pump body.

3. A pump as claimed in claim 2; said pump body comprising a lower bowlportion and an upper housing portion releasably secured together and anannular seating groove in at least one of the portions; and saiddiaphragm having an outer marginal bead clamped in said groove betweensaid body portions.

4. A pump as claimed in claim 1; each valve ball having a diametervarying in the range of approximately to percent of the diameter of theflow passage.

5. A pump as claimed in claim 1; each valve ball having a diameter equalto approximately 130 percent of the diameter of the flow passage.

6. A pump as claimed in claim 1; said valve balls having a specificgravity in the range of to 380 percent of the specific gravity .of themixture.

7. A pump as claimed in claim 1; said valve balls having a specificgravity of about 3.7 to 4.0.

8. A pump as claimed in claim 1; said valve balls being formed of a hardceramic material.

9. A pump as claimed in claim 1; each valve ball, when unseated,cooperating with its respective valve seat to define an annular venturipassage which serves to restrain excessive departure of the valve ballfrom the seat upon upward flow of mixture through the passage and toaccelerate closing action upon reverse flow.

10. A flow-through piston particularly adapted for verticalreciprocating movement in a vertically extending pump body to pumpslurries, comprising: a generally horizontally extending piston head ofcircular planform and of substantially greater diameter than thickness;said head being provided with marginal sealing means for sealing contactwith the wall of the pump body; a set of three vertical flow passages ofequal diameter extending through said head, equally spaced radially fromthe vertical axis of said head and equally spaced angularly about saidaxis; an elastorneric sealing ring mounted on said head about the uppermargin of each of said passages and being of substantially the samediameter as said passages; a clamping plate overlying said head andhaving three vertical apertures therein so located and of such size asto overlie the outer margins of each sealing ring to clamp them in placeon said head; a central guide pin and a plurality of peripheral guidepins extending vertically above said clamping plate and having reducedshank portions passing through said clamping plate and secured to saidhead and forming shoulders to engage said clamping plate and secure itin position; a set of three balls, one associated with each of saidpassages and adapted to seat by gravity on said sea-ling rings and to befreely raised vertically by relative upward movement of slurry materialthrough said passages and restricted in lateral displacement by saidguide pins; and a supporting spider frame having elements connected tomarginal portions of said head and extending upwardly and inwardly to acentral junction spaced above said valve balls and guide pins; saidframe having means at said junction for attachment to an actuatormember.

11. A pump adapted for handling liquid pulp mixtures or slurriescomprising: a hollow pump body having a mixture inlet in its lowerportion and a mixture outlet in its upper portion; a generallyhorizontally extending partition in the lower portion; a plurality ofgenerally vertically directed circular apertures forming flow passagesthrough said partition; a valve ball associated with each seat andfreely vertically movable upwardly out of contact therewith to providean annular flow path for upward movement of a mixture through saidpartition and movable downwardly into contact with each seat to form aseal therewith and prevent reverse flow; a piston in said pump body andvertically reciprocatable to pump a mixture upward through said pumpbody to said outlet; said piston having a generally horizontallyextending head provided with means to engage sealingly the wall of thepump body; a plurality of generally vertically directed aperturesforming flow passages through said head; each aperture having an annularvalve seat; a valve ball associated with each seat and freely relativelymovable vertically upwardly out of contact therewith to provide a flowpath for relative upward movement of a mixture through said head andrelatively movable downwardly into contact with each seat to form a sealtherewith and prevent reverse flow; said partition and piston head eachbeing provided on its upper surface with an elastomeric ring surroundingeach flow passage for sealingly receiving a valve ball; an aperturedclamping plate having aperture margins overlying marginal portions ofsaid elastomeric rings; vertically extending guide pins for limitinglateral movement of said valve balls; said guide pins passing throughsaid clamping plates and being secured to the partition and piston headrespectively to lock said clamping plates in clamping relation; andmeans to raise said head with its valves closed to pump mixture upwardin the pump body to the outlet and draw additional mixture through thepartition, and to lower said head with its valves open into theadditional mixture in the lower portion of the pump body.

References Cited UNITED STATES PATENTS 992,837 5/1911 Winterhotf 103-1511,036,398 8/1912 Winterhoff 103-178 1,791,615 2/1931 Dorr 103-4512,308,876 1/ 1943 Hammett 137512.l 2,405,322 8/1946 Nisbet lO3-225FOREIGN PATENTS 175,375 2/ 1922. Great Britain.

DONLEY J. STOCKING, Primary Examiner.

WILLIAM L. FREEH, Examiner.

